A number of high-profile websites, including X and ChatGPT, went down for many on Tuesday, due to problems affecting the major internet infrastructure firm, Cloudflare.

Thousands of users began reporting issues with the sites, as well as other services, to outage monitoring site Downdetector shortly after 11:30 GMT.

Cloudflare said the "significant outage" occurred after a configuration file designed to handle threat traffic did not work as intended and "triggered a crash" in its software handling traffic for its wider services.

"We apologise to our customers and the Internet in general for letting you down today," it said in a statement.

"Given the importance of Cloudflare's services, any outage is unacceptable," the company added.

It said that while the issue had been resolved, some services might still encounter errors as they came back online.

A wide range of apps and websites were impacted by the outage.

Users reported encountering delays or technical issues when trying to access services such as Grindr, Zoom and Canva.

Meanwhile, social media platform X (formerly Twitter) was displaying a message on its homepage for some users, which said there was a problem with its internal server due to an "error" originating with Cloudflare.

ChatGPT's site was also displaying an error message telling some users, "Please unblock challenges cloudflare.com to proceed."

What is Cloudflare?

Cloudflare is a huge provider of internet security across the world, carrying out services such as checking visitor connections to sites are coming from humans rather than bots.

It says 20% of all websites worldwide use its services in some form.

The range of sites affected was demonstrated by the fact Downdetector itself - a site many flock to when sites stop loading or appear to have issues - also displayed an error message as many tried to access it on Tuesday.

Alp Toker, director of NetBlocks, which monitors the connectivity of web services, said the outage "points to a catastrophic disruption to Cloudflare's infrastructure".

"What's striking is how much of the internet has had to hide behind Cloudflare infrastructure to avoid denial of service attacks in recent years," he told the BBC - highlighting how the company aims to protect sites against malicious attempts to overwhelm them with traffic requests.

He said that however, as a result of this - and the convenience of its services - it had also become "one of the internet's largest single points of failure."

Cloudflare has stressed the problem was the result of a technical problem.

"To be clear, there is no evidence that this was the result of an attack or caused by malicious activity," it said in its statement.

The company's share price was trading around 3% lower shortly after 15:00 GMT.

Issues affecting Cloudflare's services come after an outage impacting Amazon Web Services last month saw more than 1,000 sites and apps knocked offline.

Another major web services provider, Microsoft Azure, was also affected shortly afterwards.

"The outages we have witnessed these last few months have once again highlighted the reliance on these fragile networks," said Jake Moore, global cybersecurity advisor at ESET.

"Companies are often forced to heavily rely on the likes of Cloudflare, Microsoft, and Amazon for hosting their websites and services, as there aren't many other options."